Cutter for gears.



I. E. GLEASON & A. L. STEWART.-

CUTTER FOR GEARS.

APPLICATION FILED SEPT. I5. 1916.

Patented Dem M, 119111;.

2 SHEETS-SHEET K l/VVE/VTOR5 I foams 0m Amf/az1-[ 55 I. E. GLEASON (I: A. L. STEWART.

CUTTER FOR GEARS.

APPLICATION FILED SEPT. 15 I916.

2 SHEETSSHEET 11m Ana/WW K m l l M m P.

t'll titl til

JAMES E. GLEASON AN 1) ARTHUR L. STEWART, OF ROCHESTER. NEW YORIL ALSSIGNORS TO GLEASON WORKS, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

CUTTER FOR GEARS.

Specification of Letters Patent.

original application filed December 26, 1914, Serial No. 879,026. Divided and this application filed September 15, 1916. Serial No. 120,237.

To all whom it may concern:

Be it known that we, JAMES E. GLEAsoN and ARTHUR L. STEWART, both of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Cutters for Gears; and we do hereby declare the following to be a full, clear, and exact description of the same, reference being, had to the accompanying drawings, forming a part of this specification, and to the reference characters marked thereon.

The present invention relates to cutters for ears, wheels and analogous structures, and as particular reference to the production of what are known as curved or spiral teeth, and one object is the provision of a cutter which may be employed to produce curved or spiral toothed gears according to a hobbing system, involving a continuous indexing motion of the gear blank while the cutter is rotated and each blade or cutting member is presented tolthe blank in such a manner as to successively engage difi'erent teeth making a single out upon a tooth dur ing every complete rotation of the blank. Inasmuch as the blank and cutter are both continuously rotated by such relative movements as to effect complete cutting of the teeth, the machine may be said to operate, on a hobbing principle, and a further purpose of the invention to construct a cutter of novel character with the blades arranged so as to permit clearance and prevent dragging the heel of the cuttinr portion during the passage through a tooth space, and also to provide other improvements as to the construction and arrangement of cutter blades in order to permit the necessary adjustments for lining up the blades with reference to the center of the support and to insure proper spacing between successive blades,

and also their proper positioning on the cutter head to maintain a uniform depth oi cut and effective pressure angle. To these and other ends the invention consists in cer- "tain improvements and combinations of Fig. 3 is a perspective view of one of the blades;

Fig. 4 is a side view of the same;

Fig; 5 is a diagrammatic View showing the relation of cutter and blank during the cutting operation on a gear;

Fig. 6 is a similar view in diagram illustrating the relation of cutter and blank in forming a gear to mesh with that shown in Fig. 5;

Fig. 7 is a partial plan view of the cutter;

Fig. 8 is a similar view of a modified form of a cutter;

Fig. 9 is-a detail view showing the cutting relation of blank and cutter of the form illustrated in Fig. 7 and Fig. 10 is adiagrammatic view in plan showing the cutting relation of the blank and cutter disclosed in Fig. 7.

Similar reference characters throughout.

which is applicable for the production of teeth, especially upon gears of the bevel type, and other work of a similar nature involving the production of slots or teeth that are curved continuously from end to end. In the art of gear cutting generally, it has been proposed to form teeth upon the arcs of spirals as well as upon the arcs of circles and it is a characteristic of the present improvement that the tooth produced as well as the cutting portion utilized in the cutting of the tooth, are formed u on the arc of a roulette resulting from a bobbing action of a series of blades equally spaced upon a cutter head and brought into cutting relation with the blank by rotating the head and at the same time imparting a continuous rotation to the blank so that the independent blades cooperate successively with difierent portions upon the blank. The cutting portion 55 which passes the bolt 4 and it will thus be successive teeth.-

of each blade has the curvature of a roulette,

with its back portion or heel offset with relation to the front or to the path of'the cutting edge and the outer end and sides of the cutting portion are relieved, thus insuring complete clearance between the blank and cuttin portion except as to the cutting edge of t e latter. The blades may be formed for cutting either alternately upon opposite sides of teeth or all upon corresponding sides of different teeth, in either of which cases, the successive blades must be equally spaced from one another so that they may enter the blank at exactly the proper point during the continuous movement of the latter to cooperate properly with According to another modification of the invention the bladesmay be arranged in pairs, the cutting portions of each pair operating on adjacent sides of adjacent teeth at the. same time, and being equally spaced from the corresponding cut,-

tinlg portions of the next adjacent pair. n' the construction shown in the drawings, which is intended merely as illustrative of a practical method of carrying out the invention, 1 designates a head or su port adapted to be mounted upon a spin e or other rotating, element and turned continuously during the cutting operation. The head 1 is provided in its periphery with a series of slots or openings 2 to receive the blades, each of which includes a base portion' 3 and a cutting portion that will be more fully described presently. Each blade is held in position by a bolt 4 passing through an opening in the base portion 3 and engaging a threaded opening 5 in the head 1. Each blade is arrangedfor radial adjustment with reference to the head in order to bring the cutting edge closer to'or farther away from the center of the head.

inclined face 6 and the base portion 3 of the blade, is an adjusting or wedge member 7 which is movable transversely or axially of the head toefi'ect radial adjustment of the blade. The wedge 7 is adjusted by means of aset screw 8 engaging a threaded 0pening in the head and having an enlargement 91 which cooperates with a recess or opening 10 in the wedge 7. The wedge 7 is also provided with, a central opening 11 through seen that by loosening the bolt 4:, any radial adjustment of the blade canbe had by turn yto bep .operly positioned, with the outermost points of the several cutting edges all a single plane perpendicular tothe rotary axis of the head and also makes it possible to readily make the required change in the position of a blade as the cutting edge is ground away and new portions of the blade each blade can be used throughout very nearly the entire length of the cutting portion, and until the latter is worn to such an are presented to the work. By this means 1 extent that there is not suflicient material roulette, and the back portion or heel of the cutting portion is offset with reference to the front or to the path of the cutting edge,-

in order to afford proper clearance in dpassing through-a tooth space, the outer en and sides being reli'evedtoward the back to fully insure such clearance, and any section through the cutting portion ina plane radially of the cutter axis has a trapezoidal form, of the same contour as any other .radial section. According to the forms disclosed in Figs. 5, 6 and 7 the cutting portions of alternate blades have their cutting edges on the inside while on the remaining blades the cutting edges are on the outside, and with this arrangement for each setting of a blank only the alternate blades perform a cutting operation, the remaining ones being inactive and passing through a tooth space without engaging the work. In the arrangement shown in Fig. 5 the cutting portions 1 marked a: make a out each time they pass through the blank, while those marked are inoperative. After the teeth are comp eted on'one side, the blank is reset, and the cutting portions 3/ operate on the opposite sides of the teeth, while the cutting portions :11 are inactive. Fig. 5 shows 'a diagramamtic arrangement for cutting a gear, while a reverse arrangement is shown in Fig. 6 for cutting a pinion, and in Figs. 8, 9 and 10 there is illustrated a further modification Where the blades are arranged in pairs, the

cutting portions of each pair being adapted to pass through a tooth space successively and cut on the adjacent sides of adjacent teeth. Thus the cutting portions 0 and (Z cut on the sides 0 and d, while the cutting portions 6 and f, constituting the next pair on the cutter head, cut the sides e and f of the teeth forming the next tooth space. With this arrangement of blades, the distance between successive pairs is a constant one and the distance between the cutting edges of each pair is constant. The distance were between the cutting edges of each air of blades is in the same ratio to the distance between the last cutting edge of the pair and the initial cuttingedge of the next pair, as

g the width of the base of a tooth space at one edge bears to the distance from the base of one tooth space to the base 'of the next ad cations within the scope of the appended claims characterized by a cutting portion -of roulette curvature, for'producing a curved tooth by continuous rotation of cutter and blank, as well as the general ty e of cutter blade adjusting means described? We claim as our invention:

' 1. A gear cutter comprising a head or support adapted to be rotatcdand a blade p5 secured thereto having a cutting portion curved from front to back and adjustableradially of the. head.

2. A gear cutter comprising a head or support adapted to be rotated and .a blade sew cured thereto having a "cutting portion curved on the arc' of a roulette from-front to back.

3. A gear cutter comprising a head or supportadapted to be rotated and a blade 35 secured thereto having a cutting portion curved on the arc of a roulette from front to back and adjustable radially of the head. a 4. A gear cutter blade having a cutting portion, formed' on the arc of a roulette.

my 5. A gear cutter comprising a head for supportadapted to be rotated and having a slot or opening in its periphery, a blade having a base portion engaging said recess and an adjustable member arran ed between the 45 blade and the head and a justable transversely of the head for edecting radial adjustment of theblade. 1 i

6. A gear'outt'er comprising a head or support adaptedto be rotated and having a slot or opening in its periphery, a blade having a base portion engaging said recess and a cutting portion curved from front to back, A and an adjusting member arranged between the blade and the head and adjust- 5 able transversely of the head for edecting radial adjustment of'the blade.

7. A gear cutter comprising a head or support adapted to'berotated and having a slot or opening in its periphery, a. blade having a 6( base portion engaging said recess and a cutting portion curved on the arc of a roulette from front to back, and an adjusting member arranged between the blade and the head and adjustable transversely of the head 5 for eflfecting radial adjustment of the blade.

plication 'is. intended to cover any modifi-l' cutting edge to .afiord clearance in passing W5 through a tooth space.

10. A bevel ge'ar cutter consisting of a head or support adapted to be rotated and a plurality of blades secured thereto and having cutting portions extending beyond the adjacent side face of the head in the direction of its axis and spaced for successive engagement with difl'erent teeth on a blank.

11. A gear cutter consisting of a head or 35 support adapted to be rotated and a plurality of blades secured thereto and having cutting portions extending beyond the ad jacent side face of the head in the direction of its axis, and spaced for successive engage- Wm ment with difi'erent teeth on a blank, each Iguttling portion being curved from front to ac v 12. A gear cutter consisting of a head or support adapted to be rotated and a plu- 1 rality of blades secured thereto having cutting portions extending beyond the adj acent side face of the head in the direction of its axis and spaced for successive engagement with difierent teeth on ablank, each Mm cutting portion being curved from front to back on the arc of a roulette. 13'. Agear cutter consisting of a head or support adapted to be rotated and a plurality of'blades secured thereto and having cutting portion extending beyond the ad- 'ja'cent side face of the head in the direction of its axis and spaced for successive engagement with diderent teeth on the blank, each cutting portion being curved up from front to back and odset' toward its back withreference to the path of the cutting edge to adord clearance in passing through a tooth space.

If. A gear cutter consisting of a head or 1M support adapted to be rotated and a plurality of blades secured thereto and having cutting portionsextending beyond the adjacent side face of the head in the direction of its axis and spaced for successive engage- 12% and adapted to succesively engage diflerent teeth on a blank.

' 16. A'gearcutter consisting of ahead or support adapted tobe rotated, and a plurality of independent blades secured thereto and arranged in pairs, the pairs of blades being equally spaced and each pair adapted to cut on the adjacent faces of two adjacent teeth forming one tooth space, while each 10 successive-pair of blades isadapted to passthrough diiferent tooth spaces.

17.- A gear cutter consisting-of ahead or support adapted to be rotated, and a plurality of independent blades arranged circularly'of the center of the head, the blades having cutting portions ofi'set from front to back with reference to the path of the cutting edge, and adapted to successively engage different teeth on a blank.

JAMES E. GLEASON. ARTHUR L. STEWART.

Witnesses: v

A. G. VAYO, v .E. BULnooK. 

